Means for and method of forming an expansion joint



June 1966 w. M. COOPER ETAL 3,255,680

MEANS FOR AND METHOD OF FORMING AN EXPANSION JOINT- Filed Oct. 22, 1962 INVENTORS WILLIAM M. COOPER JAMES T. THORP, Jr. n. Md. Powell ATTORNEY.

United States Patent "ice 3,255,680 MEANS FOR AND METHOD OF FORMING AN EXPANSION JOINT William M. Cooper and James T. Thorp, In, St. Louis, Mo., assignors to Joint Controls, Inc., St. Louis, Mo., a corporation of Missouri Filed Oct. 22, 1962, Ser. No. 231,888 Claims. (Cl. 94-18) This invention relates generally to improvements in means for and the method of producing an expansion joint, and more particularly to a sealing device adapted to form an expansion joint in pavement and to the method of installing such device.

In the placing of cement pavement, it is conventional to provide expansion joints between sections of pavement to permit thermal expansion of the sections while in use. There are a number of different types of expansion joints. For example, hot asphaltic or equivalent material can be poured into spaces provided between pavement sections, or extruded or otherwise preformed slab-like strips can be inserted int-o such spaces. Most of these types will not react satisfactorily to keep the spaces filled and weatherproof as the spaces are enlarged by contraction of the pavement sections under falling temperatures. Furthermore,.in some methods of construction, the space is formed by cutting a slot in the finished pavement with a suitable blade or abrading disc, which procedure is timeconsuming and costly.

It is an important object of the present invention to provide a sealing device adapted to be placed in newly poured pavement, the device including an elongate strip with an attached block, the block being of a material characterized by compressibility yet having inherent slow recuperative expandability.

Another important object is achieved by constructing the sealing device with the elongate block attached to and extending laterally on each side of an upper portion of the strip, and with an upwardly diverging channel below the block on the lower portion of the strip, the channel precluding floating action of the device in the freshly placed concrete pavement during setting.

Still another important objective is realized by making the block of polyurethane foam that can be easily compressed yet capable of returning by expansion slowly to its original dimension or substantially thereto. Other advantages are afforded by impregnating the cellular structure of the foam with asphalt that cooperates to form an effective seal upon contraction and expansion of adjoining pavement sections between which the device is used.

Another important object is obtained by the provision of a thin membrane on the outer surface of the sealing block material which serves to retard or delay the inherent spring-back characteristic of the block material for a sufficient time to allow the'concrete to set before complete expansion of the block is obtained, prevents adherence of the block to an installation clamp used to compress and hold the block, and holds the impregnated asphalt in the block under all conditions when asphalt is utilized. It is particularly advantageous to make the membrane of a thin polyethylene.

An important object is achieved by the provision of an expansion joint using a sealing device of the type described above in which the device is placed in the concrete before setting with the block compressed, the concrete setting before the block fully expands.

Patented June 14, 1966 Yet another important objective is realized in that the sealing block of the expansion joint expands to a greater degree at its outermost portion adjacent the pavement surface than at its innermost portion upon setting of the concrete, whereby the completed joint has an upwardly diverging configuration that affords strong shoulders at the pavement surface tending to reduce spalling.

An important object is provided by the method of forming an expansion joint using the sealing device which includes. the steps of compressingthe block, inserting the device into newly placed concrete with the block located adjacent the pavement surface while maintaining the block under compression, removing the compression from the block after placement, and allowing the block to expand slowly while. the concrete sets.

Another important objective is obtained by utilizing a vibrating clamping tool adapted to compress the block and to install the device in the concrete, the tool being adapted to release from the device and withdraw from the concrete while vibrating.

It is an important objective to provide a sealing device and expansion joint that is simple and durable in construction, economical to manufacture, and highly eflicient in operation.

The foregoing and numerous other objects and advantages of the invention will more clearly appear from the following detailed description of a preferred embodiment, particularly when considered in connection with the accompanying drawing, in which;

FIG. 1 is an end elevational view of the sealing device;

FIG. 2 is a fragmentary side elevational view as seen from the right of FIG. 1;

FIG. 3 is a fragmentary cross sectional view illustrating the sealing strip installed with a clamping tool;

FIG; 4 is a fragmentary cross sectional view showing the sealing strip installed, with the clamping tool removed, and

FIG. 5 is a fragmentary cross sectional view of the completed expansion joint.

Referring now by characters of referenceto the drawing, and first to FIGS. 1 and 2, it is seen that the sealing device includes an elongate metal strip generally indicated at 10 having an upper portion 11 and a lower portion 12. It will be noted that the strip 10 can be constructed of a one piece unit or can be constructed of two mating sections arranged and secured together in back-toback relation.

The lower portion 12 of elongate strip 10 is provided with flanges 13, one of which extends laterally and upwardly from each side of the lower edge of the strip 10, the flanges forming an upwardly divergent channel 14. The purpose and functional advantages provided by channel 14 will be subsequently described.

Secured by a bonding agent to the upper portion 11 of elongate strip 10 is an elongate block 15 formed of a material characterized by compressibility yet having inherent slow recuperative expandability. Preferably, the block 15 consists of a polyurethene foam. This material can be easily compressed but will assume its original dimensions very slowly.

Specifically, the upper portion 11 of strip 10 is embedded in the block 15 so that the block 15 extends above the upper margin of the strip and extends laterally on each side thereof. The block may be constructed of two pieces bonded together and to the opposite sides of the strip upper portion 11. To provide a more effective bond, the strip upper portion 11 may be provided with a plurality of staggered, spaced holes 16 through which the block material can extend and be bonded together.

The block material of polyurethene foam is a cellular structure having the characteristics mentioned previously and is capable of being impregnated with ductile asphalt that cooperates with the foam to achieve an effective seal in an expansion joint.

The outer surface of block 15 may have a thin membrane 17, the purpose of which will become apparent upon later description of parts and methods of installation. Preferably, this thin membrane will consist of polyethylene that can be sprayed on the block 15. In one embodiment in which a membrane 17 is utilized, good results have been obtained by using a polyurethane foam and seventy percent asphalt by weight.

An elongate clamp generally indicated at 20 in FIG. 3 is adapted to insert the sealing device into newly placed concrete indicated at 21. The clamp 20 includes a pair of clamp arms 22 hingedly connected at one end along an axis 23. Preferably, the clamp arms 22 are provided with a plastic coating such as Teflon that prevents the block material from adhering.

To install the sealing device and form an expansion joint, the block 15 is placed between the clamp arms 22. Pressure is exerted by the clamp 20 whereby the clamp arms 22 compress opposite sides of the block 15 along its length. While the clamp 20 holds the block 15 in a compressed condition, as is illustrated in FIG. 3, the sealing device is inserted into the newly poured concrete 21.

This placement of the sealing device is accomplished by pushing the sealing device into the concrete 21 with the channel 14 foremost until the upper edge 24 of the block 15 lies closely adjacent and substantially flush to the pavement surface 25. To facilitate the insertion of the sealing device with the least disturbance of the concrete 21, the sealing device is vibrated by the clamp 20 as it is moved inwardly into place.

After the sealing device has been positioned, the compressive forces exerted on opposite sides of the block 15 by the clamp arms 22 is released, and the clamp 24) is withdrawn from the concrete 21 while the clamp 20 is vibrated. As the clamp 20 is withdrawn, the concrete 21 flows immediately into contact with the block 15, as is illustrated best in FIG. 4. Of course, it will be readily understood that the block 15 will not immediately expand to its original dimension because of the unique characteristics of the material. The channel 14 coacts with the concrete 21 to prevent the sealing device from floating or otherwise moving outwardly after it has been placed.

In using a sealing device that has a membrane 17 on the block 15, it will be undestood that such membrane prevents the block 15 from adhering to the clamp arms 22 during installation and during withdrawal of the clamp 20, and also serves to slow expansion as the concrete 21 sets up, which normally takes about fifteen minutes and upwardly.

As the concrete 21 sets, the block 15 will slowly expand. However, because of the nature of the material constituting block 15, the concrete 21 will set before the block 15 has fully expanded. FIG. 5 illustrates the position and configuration assumed by the block 15 upon setting of the concrete 21. Because the resistance of the concrete 21 is greater toward the inside than toward the pavement surface 25, the block 15 will expand to a greater degree at its outermost portion than at its innermost portion. This result means that the block will have an upwardly divergent configuration and will form contiguous lateral walls 26 having a conforming shape. These inclined walls 26 extend upwarly to the pavement surface 25 to provide strong shoulders 27 that tend to reduce spalling.

Upon contraction of the concrete 21 on opposite sides of the sealing device under falling temperatures, there will be a tendency for the distance between the lateral walls 26 to increase. However, upon any increase in lateral dimension, the block 15 will slowly expand to keep the space filled and weatherproof. Conversely, upon thermal expansion of the concrete 21, the block 15 is compressible to accommodate any variation in distance between the lateral concrete walls 26.

Although the invention has been described by making detailed reference to a single preferrred embodiment, such detail is to be understood inan instructive, rather than in any restrictive sense, many variants being possible within the scope of the claims hereunto appended.

We claim as our invention:

1. A sealing device comprising:

(a) an elongate block of material characterized by compressibility yet having inherent slow recuperative expandability whereby said block will tend to expand to its original shape after compression,

(b) a flat elongate strip of material having sides and opposing edge portions, one of said edge portions being embedded in said elongate block, the elongate block extending :beyond said edge portion and on each side of said strip,

(0) said other edge portion having ing toward said one edge portion from and from the elongate block.

2. A sealing device as claimed in claim 1, wherein said elongate block is formed of polyurethane foam containing asphalt.

3. The method .of forming an expansion joint using a sealing device having an elongate strip and an elongate block secured to the strip, the elongate block being of a material characterized by compressibility yet with recuperative expandability, the method comprising the steps of:

(a) compressing the elongate block,

(b) inserting the device into newly placed pavement before the pavement sets so that the elongate block is located adjacent the surface of the pavement while maintaining the elongate block under compression,

(0) removing the compression from the elongate block,

and

(d) allowing the elongate block to expand slowly while the pavement sets, the compression being removed from the block at a time so that the pavement sets before the block has fully expanded.

4. The method of forming an expansion joint using a sealing device having an elongate strip, an elongate block secured to the upper portion of the strip and extending laterally on each side thereof, and an upwardly diverging channel on the lower portion of the strip below the elongate block, the elongate block being of a material characterized by compressibility yet having inherent slow recuperative expandability, the method comprising the steps of:

(a) compressing opposite sides of the elongate block,

(b) inserting the device into newly placed pavement before the pavement sets so that the channel is fully embedded and so that the upper edge of the elongate block is located adjacent the surface of the pavement,

(c) maintaining the elongate block under compression while inserting the device,

(d) removing the compression from the of the elongate block,

(e) and allowing the elongate block to expand slowly while the pavement sets, the elongate block expanding in a greater degree at its outermost portion ad jacent the pavement surface than at its innermost a channel divergand spaced thereopposite sides portion upon setting of the pavement to form an upwardly divergent slope and to form lateral pavement walls having a conforming slope extending to the pavement surface, the compression being removed from the block at a time so that the pavement sets before the block has fully expanded.

5. The method of forming an expansion joint using a sealing device having an elongate strip, an upwardly diverging channel on the lower portion of said-strip, and an elongate block secured to the upper portion of the strip above the channel, the elongate block being of a material characterized by compressibility yet having inherent slow recuperative expandability, the method comprising the steps of:

(a) compressing opposite sides of the elongate block with a clamping tool,

(b) inserting the device into newly placed pavement before the pavement sets with the channel entirely embedded and with the outermost edge of the elongate blocklocated closely adjacent the pavement surface,

(c) vibrating the device upon insertion,

(d) removing the compression from the elongate block and withdrawing the tool from the pavement while vibrating the tool, and

(e) allowing the elongate block to expand slowly While the pavement sets, the elongate block expanding-a greater degree at its outermost portion near the' pavement surface than at its innermost portion upon setting of the pavement to form an upwardly divergent slope and to form lateral pavement walls having a conforming slope extending to the pavement surface, the compression being removed from the block at a time so that the pavement sets before the block has fully expanded.

References Cited by the Examiner UNITED STATES PATENTS 1,460,841 7/1923 Briody 94-51 1,730,067 10/1929 Fischer 94-18.2 1,743,814 1/ 1930 Galassi 94-'18.2 1,960,374 5/1934 Edmonds 94-18.2 1,974,327 9/1934 Bostwick 9 418.2 2,315,588 4/ 1943 Brickman 94-18.2 2,540,251 2/ 1951' Fischer 94-18 2,964,424 12/1960 Mast 94-18.2 2,967,467 1/1961 Maude 9'4-18.2 3,038,395 6/1962 Middlestadt 94-18 3,052,945 9/1962 Cummings 94-51 X 3,136,022 6/1964 Dohren 94-51 X 3,180,238 4/1965 Crone 9418 OTHER REFERENCES Roads and Streets, publication, March 1960, page 133.

CHARLES E. OCONNELL, Primary Examiner. JACOB L. NACKE-NO'FF, Examiner.

N. C. BYERS, Assistant Examiner. 

1. A SEALING DEVICE COMPRISING: (A) AN ELONGATE BLOCK OF MATERIAL CHARACTERIZED BY COMPRESSIBILITY YET HAVING INHERENT SLOW RECUPERATIVE EXPANDABILITY WHEREBY SAID BLOCK WILL TEND TO EXPAND TO ITS ORIGINAL SHAPE AFTER COMPRESSION, (B) A FLAT ELONGATE STRIP OF MATERIAL HAVING SIDES AND OPPOSING EDGE PORTION, ONE OF SAID EDGE PORTIONS BEING EMBEDDED IN SAID ELONGATE BLOCK, THE ELONGATE BLOCK EXTENDING BEYOND SAID EDGE PORTION AND ON EACH SIDE OF SAID STRIP, (C) SAID OUTER EDGE PORTION HAVING A CHANNEL DIVERGING TOWARD SAID ONE EDGE PORTION AND SPACED THEREFROM AND FROM THE ELONGATE BLOCK. 